Process for the destruction of insect pests



Aug. 20, 1929. A. M. KOBIOLKE 1,725,650

PROCESS FOR THE DESTRUCTION OF INSECT PESTS Filed July 27, 1927 4 Sheets-Sheet l 1929- A. M. KOBIOLKE 1,725,650

PROCESS FOR THE DESTRUCTION OF INSECT PESTS Filed July 27, 1927 4 Sheets-Sheet 2 27 ,6 ml, flm

Aug. 20, 1929. A. M. KOBIOLKE 1,725,650

PROCESS FOR THE DESTRUCTION OF INSECT PESTS Filed July 27, 1927 4 Sheets-Sheet 5 min mhilili N I] Mumm [ii]: il

1929- A. M. KOBIOLKE 1,725,650

PROCESS FOR THE DESTRUCTION OF INSECT PESTS Filed July 27. 1927 4 sheets-sheet 4 Patented Aug. 20, 1929.

UNITED STATES ADOLF MARTIN KOBIOLKE,

OF GILDEROY, AUSTRALIA.

PROCESS FOR THE DESTRUCTION OF INSECT PESTS.

I Application filed July 27, 1927, Serial No. 208,889, and in Australia August 10, 1926.

This invention relates to a process and apparatus for the destruction of insect and other pests in food products and other material and has been devised in order to provide a cheap, simple and effective process to accomplish this object.

An essential feature embodied in the invention consists in the application of bisulphide gas in unadulterated form so as to ensure a direct application of the gas, which is not only economical in practice, but is deadly to insect and other pests.

The process embodied in the invention consists in first Withdrawing the oxygen, which is the natural food to all life, from the kiln and material to be treated by means of a vacuum of as high a degree as possible and then closing the vacuum valve. As it is practically impossible to create a complete vacuum there remains a highly rarefied atmosphere in the kiln and the removal of as much of this atmosphere as possible is necessary. This is attained by circulating carbon monoxide gas through the kiln which absorbs any remaining oxygen and continues until the kiln area reaches atmospheric pressure. As carbon monoxide is a poisonous element it must be removed and this is accomplished by the application of vacuum drawn at about twentyfive inches and during, or after, this operation bisulphide of carbon gas is drawn by the vacuum into the kiln and into the pores of the products being treated. The penetration is carried on to a sufiicient degree and according to the density of the material being treated the gas being unadulterated as it has not had any contact with oxygen and not being diluted with air the poisonous gas is thus deadly to all insects, larva or eggs. The bisulphi-de of carbon gas is then withdrawn by the vacuum producing device and exhausted to the atmosphere, the vacuum being created in the kiln to a higher degree than in its application for fumigating above described.

The main air inlet valve is then opened and air rushes into the kiln at the same time the vacuum pump and circulating fans are operating to create a maximum of agitation for ensuring a thorough air cleansing of the materials treated and after this operation the goods are clean and free from insect life in any form.

A further essential feature embodied in the process consists in the removing of the oxygen in the kiln by vacuum, then burning any remaining oxygen in the kiln by the circulation therethrough of carbon monoxide created by air rushing through a charcoal fire directly into the kiln.

A further essential feature embodied in the process consists in creating a vacuum in the kihi after the oxygen therein has been removed and then drawing bisulphide of carbon gas into the kiln and pores of the products and to hasten the vapourizing of the bisul-- A further essential feature embodied in the process consists in the treatment of the roducts with bisulphide of carbon gas, app ying a high vacuum and then suddenly releasing the vacuum to cause a sudden rush of air to force the gas through the open pores of the products being treated.

In order that the invention may be more readily understood it will now be described with reference to the accompanying drawings in which Figure 1 is a view in side elevation.

Figure 2 is a view in plan.

Figure 3 is a view in rear elevation, and

Figure 4 is a view in front elevation of the apparatus, this view being partly in section with the kiln door removed.

, According to this invention a kiln 1 is provided having fan inlet pipes 2, 3 with control valves 4, each pipe 2, 3, leading to a fan 5.

The fans 5 also circulate through the bottom of the kiln 1 by the pipes 6, 7 leading to the branch pipes 7, 8 communicating with the respective ends of the kiln 1 as at 8 and 9.

The fans 5 and pump 13 are suitably driven by belt or the like from any suitable source of power.

The pipes 7 and 8 are fitted with control valves 10.

A pipe 11 with control valve 12 leads from thekiln 1 to a suction pump 13 or other vacuum producer.

Within the kiln 1 at the top and bottom are steam coils 14, respectively fed from a boiler 16 through the pipes 17, 18 fitted with control valves 19 and delivering respectively past the traps 20 to atmosphere.

The walls of the kiln 1 are insulated as at 21 and on each side is a gutter 22 receiving the condensed moisture in the kiln 1 and delivering through pipes 23 to an hermetically sealed bottle 24 dis used in the pit 25 and a control valve 26 is tted to the pipes 23.

The material to be treated is run into the kiln 1 on trucks 26 with wheels 27 running on rails 28 on the kiln floor while the door 29 at the front is hermetically sealed in any suitable way.

A steam pipe 30 leads from the boiler 16 to a steam coil or jacket 31 of a bisulphide of carbon container 32, the latter being fitted with the steam exhaust 33 and trap 34.

The bisulphide of carbon gas is fed from the container 32 to the kiln 1-by the pipe 35 with valve control 36.

A charcoal burner 37 has a pipe lead 38 and filter 39 of suitable construction past a valve 40 to the kiln 1.

In the process and o eration the kiln 1 receives the food or ot ier, material to be treated on the trucks 26 or in any other suitable manner and the door is then hermetically sealed.

The oxygen in the kiln 1, which is the natural food of all life, is then withdrawn from the kiln 1 bycreating a vacuum of high degree and after withdrawing the air the vacuum valve 12 in the pipe 11 leadingto the vacuum producer 13 is closed.

As it is practically impossible to create a complete vacuum in the kiln 1 there still remains a highl rarefied atmosphere in the kiln and it is necessary therefore to remove as much as possible.

To attain this, carbon monoxide is circulated through the kiln 1 by opening the valve .40 of a charcoal burner 37 which has already been fired and this allows the carbon monoxide-gas to rush from the fire at atmospheric pressure into the kiln and over the surfaces thereof, to allow the carbon monoxide toabsorb any available oxygen and this continues until the kiln area reaches atmospheric pressure.

As carbon monoxide is a oisonous gas it must then be removed and by doing so the last trace of oxygen is also removed.

This is efl'ected by drawing a vacuum in the kiln 1 at about twenty-five inches and at this period a valve 36 of the pipe 35 leading from the bisulphide of carbon container 32 is opened causing the bisulphide of carbon to boil and be drawn in vapour form into the kiln and pores of the products being treated.

To facilitate the vapourizing of the bisulphide of carbon steam may be fed through the steam coil in the container 32.

The penetration is carried on to a sufficient degree according to the density of the material treated, a clean gas being provided which has not been in contact with oxygen and as the bisulphide of carbon gas has not been diluted with air or oxygen in any wayit is consequently more destructive to all insects, larva or eg s.

By utilizing such a highly concentrated or pure bisulphide of carbon gas a smaller relative quantity is required for treating the materials and a maxlmum degree of effectiveness is obtained than is possible when using the gas diluted with air as in existing processes.

The gas is withdrawn from the kiln 1 by the pump 13 and exhausted to atmosphere and a higher vacuum is created ,in the kiln 1 than that required in utilizing the bisulphide of carbon or fumigating gas. v

The main inlet valve 12 is then opened and air rushes into the kiln 1 while at the same are caused to operate to create a maximum of agitation so ensuring a thorough air cleansing of the materials under treatment. The goods are then clean and free from insect life in any form.

The steam coils 14, 15 at the top and bottom of the kiln 1 are used in severe cases to allow of extra heat to be imparted to the fumigating gas to increase its destructive activity in the kiln.

I desire it to be understood that the destructive gas employed may be varied to suit the articles being treated, for-instance, in lieu of the bisulphide of carbon gas, a as formed from a pyrethrum base may be use and other time the vacuum pump 13 and the fans 5 modifications may be employed without dethe kiln area reaches atmospheric pressure,

withdrawing the carbon monoxide gas by means of suction, and then drawing fumigating gas which has not had contact with air, into the kiln and pores of the product in vapor form, then withdrawing the fumigating gas by a vacuum pump, then suddenly releasing the vacuum by openingthe kiln to the atmosphere and circulating the air through the kiln.

2. Process for the purpose specified, comprising placing the material to be treated in an hermetically sealed kiln withdrawing air from the kiln by means of suction, then consuming the remaining oxygen by the circu-' lation of carbon monoxide gas in the kiln until the kiln area reaches atmospheric pressure, withdrawing the carbon monoxide gas by means of suction, and then drawing bisulphide of carbon gas from a sealed container, said gas being undiluted with air, and assisting the vaporization of the bisulphide of carbon by heat from steam coils in the container drawing the vapor of the bisulphide of carbon into the kiln and pores of the material, then withdrawing the fumigating gas by a vacuum pump, suddenly releasing the 10 vacuum b o ning the kiln to the atmosphere and circu atln the air through the kiln.

Signed at elbourne, Victoria, Australia, this 14th day of June A. D. 1927.

ADOLF MARTIN KOBIOLKE. 

